In the home feed, we recommend stories we believe the viewer might be interested in based on a variety of signals such as watch history and likeliness to watch(regardless of whether the viewer is subscribed to the channel).
We hear you. You can hit the three dot menu & select “Edit stories recommendations” to stop seeing stories from channels you’re not interested in. Also, you can share your thoughts on the feature by sending a feedback report. Here's how: https://goo.gl/WdI0BK . Hope this helps.